In the design of electrically controlled items that comprise many different types of electrical components, it is often necessary to test and evaluate the performance of each electrical component with the item being designed before the electrical component is manufactured into the item. The testing evaluates the performance of each electrical component with the item being designed, and evaluates the performance of each electrical component with other electrical components in the item being designed. This enables a determination of each electrical component being suitable for use in the item being designed before the design of the item is finalized.
For example, in the design of an aircraft, several different electrical components from different suppliers can go into the design. For example flight control components, navigation components, cabin climate control components, etc. The various different electrical components are electrically communicated through an automated test system with a test version of the aircraft to evaluate the performance of each of the electrical components with the aircraft and with other electrical components used in the design of the aircraft.
For example, flight control electrical components of different suppliers are individually communicated through the automated test system with the test version of the aircraft to evaluate that component's interfacing with the aircraft and the other electrical components of the aircraft to ensure that the particular electrical component will function satisfactorily. The existing ways of electrically communicating the different electrical components and the test version of the aircraft with the automated test system and switching between each of the electrical components to communicate each electrical component individually with the automated test system and the test version of the aircraft are cumbersome, costly and not scalable.
There are various different ways of communicating the electrical components with the automated test system and through the test system with the test version of the aircraft. According to one method, multiple different configurations of cables are built that are manually connected to the electrical component being tested and the automated test system. To selectively switch between the different electrical components of different suppliers, it is necessary to manually disconnect the multiple cables from the electrical component of one supplier and connect the multiple cables to the electrical component of another supplier for the other electrical component to be tested with the test version of the aircraft. This method is disadvantaged in that building multiple different cables needed to communicate the electrical components tested with the test version of the aircraft is both time consuming and labor intensive. Disconnecting the cables from an electrical component and then reconnecting the cables to the next electrical component can result in errors in system functionality of the automated test system. Additionally, manually disconnecting the cables and then reconnecting the cables can take hours. There is a long switch time with risks of misconfiguration (bent pins, cable swaps, etc.). Switching the cables puts wear on the automated test system connector of the cables, limiting the life of the automated testing system.
Another method of communicating each of the electrical components with the automated test system and the test version of the aircraft is to construct a separate patch panel for each of the electrical components to be tested. A separate custom patch panel is used to switch between each of the different electrical components and the automated test system and the test version of the aircraft. This method is disadvantaged in that the custom patch panels are very costly (in hardware used to create each patch panel and in the engineering time needed to create each patch panel). Furthermore, because each patch panel is custom designed for a particular electrical component, the patch panels are very under-utilized. Although, switching one patch panel out for another patch panel to communicate different electrical components with the automated test system does not require as much time as switching cables, switching the patch panels puts wear on the patch panel connectors and limits the life of the patch panel.
A Versa Module Europa (VME) bus based cabinet can also be used to switch between electrical components being tested with a test version of an aircraft through the automated test system. However, the VME cabinets are very costly to construct. The switching requires active control of hundreds of signals of multiple relay channels. The VME bus based cabinet also requires custom cables that are very costly to manufacture to interface the VME cabinet with the automated test system and the test version of the aircraft.
In addition to VME switching mechanisms, there are relay switching mechanisms in VXI (VME extensions for instrumentation), PCI (peripheral component interconnect), PXI (PCI extensions for instrumentation), and LXI (LAN extensions for implementation) formats, to name only a few. All of these share the disadvantages of higher cost per signal, higher power consumption, special interfaces to the test system controller, and custom interface cables to the equipment under test.
Custom interconnect systems have also been constructed to communicate the electrical components through the automated test system with the test version of an aircraft. These interconnect systems employ relays that are built to toggle between the separate electrical components being tested with the test version of the aircraft through the automated test system. However, custom interconnect systems are costly to design and build. They are also physically large, that limits their scalability. Switching between the electrical components requires active control of hundreds of relay signals. There are also hundreds of relays consuming power in normal operation of the custom interconnect system.